(1). Field of the Invention
The present invention relates to submersible vessels and more particularly to such vessels with ballast compensating means used in conjunction with weapons systems.
(2). Brief Description of the Prior Art
The launching of a weapon or equipment from a submersible vehicle results in significant negative buoyancy due to the release of the weight and buoyant force of the weapon or equipment. Various approaches to this problem are suggested by the prior art. U.S. Pat. No. 3,356,056 to Lehmann, for example, discloses a missile and torpedo firing submarine that carries a series of weapons on a revolving platform and ejects them from only one opening at the rear under full submergence speed. The submarine is equipped with automatic ballast in which buoyancy compensation after missile release is accomplished by water exchange.
U.S. Pat. No. 3,368,510 to Humphrey discloses a mine laying submarine in which buoyancy tanks are used to adjust trim after mine release. A valve is connected to water supply lines for admitting water to the buoyancy tanks and for expelling water form the tanks after the mines have been released.
U.S. Pat. No. 3,716,010 to Wilson et al. discloses a snap acting ballast release device for a torpedo. The hull of the torpedo has an angular release and a plurality of waste is disposed within the release. A resilient band extends around the weights and secures them in a closed bias position. Upon release of the ends of the band, the band and its attached weight snap free from the torpedo, thus releasing ballast weights to allow the torpedo to surface.
U.S. Pat. No. 4,777,819 to Hoyt et al. discloses a method and apparatus for making depth-related measurements from an unteathered, gravity driven oceanographic platform. The platform is comprised of a smooth, streamlined torpedo shaped body that releasably carries ballast in its nose and is covered with foam for buoyancy. At the appropriate depth, the ballast is released and the body ascends to the surface.
U.S. Pat. No. 5,163,379 to Chorley discloses a mine deployment system that includes ballast compensation based on the filling and emptying of ballast tanks. The rigid chamber has an opening at one end. The chamber contains air and atmospheric pressure and is sealed by a piston. The piston is held in position by a piston release to prevent from moving under pressure from the surrounding water. A buoyancy control unit is attached to an object deployment device and when the object is released the piston release is removed by solenoid pulling a cord which allows the piston to move. The decrease in buoyancy from the compression of air and filling the chamber with water compensates for the increase in buoyancy created when the object is jettisoned from the unit.
U.S. Pat. No. 5,675,117 to Hillendbrand discloses an unmanned undersea vehicle system that includes an axisymetrical, cylindrical shaped, self-propelled undersea deployment vehicle. Buoyancy tanks are provided with actuable valves to allow for a controllable path to enable seawater exterior of the weapon compartment to flow into respective buoyancy tanks during deployment and firing of the weapons.
These means are difficult to use with autonomous vehicles because they do not allow trim to be set upon provisioning of a vessel. Internal ballast tanks cannot be easily configured to instantaneously offset the ballast requirements of a weapons launch. All of these methods have the problem of creating an instantaneous force on the vehicle during filling of the ballast tank.